1. Field of the Invention
The present invention relates to an electronic flash apparatus for photographing, and more particularly to flash control of a flash discharge tube in an electronic flash apparatus for close-up photographing.
2. Description of the Prior Art
Among electronic flash apparatus for illuminating an object to be photographed, there are already known an apparatus equipped with plural flash discharge tubes for obtaining efffective illumination, and an apparatus equipped with an annular flash tube positioned around the optical axis of a photographing lens for achieving uniform illumination in close-up photographing.
The U.S. Pat. No. 4,068,245 discloses an electronic flash apparatus provided with two flash tubes positioned at the front end of a photographing lens on both sides of the optical axis thereof, and two lamps likewise positioned on both sides of the optical axis. The two flash tubes generate light emission for illuminating an object in synchronization of the film exposure. The two lamps constitute so-called modelling illumination to be turned on prior to the photographing, in order to illuminate a dark object and thus facilitate the focusing operation through a finder of the camera.
Such conventional modelling illumination device has lacked compactness, as a space for such lamps, beside that for the flash tubes, has to be provided in the flash apparatus. Also the illumination with such lamps is unable to provide enough luminance to the object, and the obtained photograph may be different from the intention of the photographer because of unexpected shadows, as the position of illumination is different from that in the actual photographing operation.